NARRATIVE OF THE CRUISE. 
839 
pelagic species, but were always filled with minute swarm spores about 0‘005 mm. in 
diameter. When a specimen was placed on a slide and crushed with a cover glass, then 
examined by a high power, a cloud of these minute bodies, with a flagellum at one end 
and a pellucid spot at the other, spread over the field of the microscope ; there was a 
bubble of air or gas in each shell. A similar condition was observed once in Globigerina 
sacculifera and once in Pullenia obliquiloculata. 
The colour of the sarcode in the pelagic Foraminifera is sometimes bright red, 
as in Hastigerina and Pullenia; in Globigerina it is yellow, orange, or of a delicate 
rose colour; in Pulvinulina micheliniana it has occasionally a decidedly greenish 
tinge. 
When observed floating on the surface, the larger part of the sarcode is usually 
outside the shell, so that the latter may not be noticed owing to the dense mass of 
Fig. 308 . — Globigerina bulloides (d’Orbigny), from the deposits. Tropical regions of the Atlantic. 
protoplasmic matter with which it is enveloped. The pseudopodia ramify to a great 
distance from the shell, and balloon-like expansions of the sarcode are thrown out 
between the spines of a shell like Hastigerina; over these and along the spines, the 
pseudopodia move freely and rapidly (fig. 305). In the species without spines, this float- 
like arrangement was never observed fully expanded ; the contact of the tow-net having 
evidently caused a collapse and a contraction of the sarcode close about the shell. On one 
or two occasions, however, the floats of Pulvinulina and Pullenia were seen partially 
expanded. 
In Orbulina there are almost always a great number of yellow cells similar to those 
found in the Radiolaria ; they are oval and about O'Ol mm. in the longest diameter, 
and have a nucleus which colours quickly with carmine, before treatment with spirit. 
On several occasions they were seen to flow out from the interior of the shell with the 
(NAUR. CHALL. EXP. VOL. J. — 1885.) 106 
